Since he is available in 2 and 3* I have to assume this is a troll post. If you haven't got him in any other *level to evaluate him yourself I'd suggest playing with him and making your own decisions before investing resources in him

I want to say both but it depends on where you're at.
I have fond memories of running him, symbiote spider-man, and a third that I can't recall in AQ when I was just starting out but that was 3ish years ago now.

Don't feel too bad my last 2 5 star crystals were both groot, the chances of that happening are so small but it happened

My first four five 5* crystals were Voodoo, Dormammu, Spark, Dormammu. I'm not complaining, but the odds are definitely weird sometimes. I think my first two 4* champs were Jane Foster and Jane Foster.